<html>
<head>
    <title>Scroll page</title>
</head>
<body>
    <h1>Simple page</h1>

    <script>
        window.onscroll = function() {
            document.getElementsByTagName('window.onscroll');
        };

        window.addEventListener('scroll', function() {
            document.getElementsByTagName('scroll on window');
        });
    </script>
</body>
</html>